Artificial joint



March lO, '1959 F. A. K. KQETKE 2,877,033-

ARTIF'ICIAL JOINT Filed March 16, 1956 2 Sheets-Sheet l March 10, 1959 F. A, K. KOETKE 2,877,033

ARTIFICIAL JOINT I Filed March 16, 1956 2 Sheets-Sheet 2 J ne; .17 I 2 196 fipeoier 'c/e 23626033562 7 5 fltfidrmy United States Patent ARTIFICIAL JOINT Friedrich A. K. Koetke, Chicago, 11]., assignor to Dreher Manufacturing Company, Chicago, 1]].

Application March 16, 1956, Serial No. 572,038 4 Claims. l. 231-99 The present invention relates to the field of artificial limbs and braces. More particularly, the invention relates to the construction of a joint for use in a wide variety of braces and appliances of that nature.

Many joint constructions are being used and many more have been proposed. By far the bulk of these devices are adapted for special uses, and are complex and expensive to construct. A long felt need has arisen for a joint which is simple to construct and yet which operates to simulate the actual joint action.

Accordingly, it is the general object of the present invention to provide an artificial joint which simulates the motion of the anatomical joint. A related object is to furnish an artificial joint which is susceptible of mass production.

Another object of the invention is to furnish an artificial joint which is simple in construction and yet adaptable to a wide variety of usages.

A more detailed object of the invention is to provide an artificial joint for a prosthesis which simulates the actual joint action faithfully so as to avoid binding at the extremities of the arc of rotation.

Further objects and advantages of the present invention will become apparent as the following description of an illustrative embodiment proceeds, taken in conjunction with the accompanying drawings in which:

Figure 1 illustrates a brace embodying a joint illustrative of the invention, the brace being attached to the thigh and calf with the joint at the knee of the wearer.

Fig. 2 shows a brace embodying a joint illustrative of the invention attached to the upper arm and the forearm of the wearer, the joint paralleling the elbow joint.

Fig. 3 illustrates a brace for use as a hip joint intended for attachment at the thigh and abdomen.

'Fig. 4 illustrates in plan view an illustrative joint with the extending brace bars at approximately right angles.

Fig. 5 is a rear view of the joint shown in Fig. 4.

Fig. 6 is an exploded view of the joint shown in Figs. 4 and 5.

Figs. 7 through 11 show the joint illustrated in Figs. 4 through 6 in sequential opening from the folded position shown in Fig. 7 to the fully opened position shown in Fig. 11.

Fig. 12 illustrates a locking mechanism for use with the illustrative joint, the unlocked or open position shown in Fig. 12.

Fig. 13 illustrates the structure shown in Fig. 12 with the locking mechanism in the locked position.

Figs. 14 and 15 are front and side views respectively of the locking joint shown in Figs. 12 and 13.

In the manufacture of artificial joints, two general elassifications of joints are found: those which replace a live joint, and those which support a live joint. The present invention finds its greatest utility in the prosthesis application where the joint supports or parallels a live joint. For this reason it is highly important that the'artificial joint closely and faithfully reproduce the motion of its associated live joint.

Most joints, for example the knee joint, do not have a fixed center of rotation but actually have a moving center or centroid. The present invention stems from the discovery of a similar phenomenon occurring in a simple linkage where a longitudinal and transverse link couple the joint defined at the abutting ends of the extremity brace bars.

Three examples of the types of braces in which the present invention may be employed are shown in Figs. 1, 2 and 3 of the drawings. assembly 10 employs a joint assembly 11 at the intersection of the upper or thigh brace bar 12 and lower or calf brace bar 14. The thigh brace bar 12 terminates in a pocket 15 in the supporting band 16 which is laced in place on the thigh 18 by means of laces 19. Similarly the thigh brace bar 14 terminates in a pocket 20 of a supporting band 21 which is laced to the calf 22 for support. In Fig. 2 the same joint assembly 11 is secured to an upper arm brace bar 24 and forearm brace bar 25. The brace bars terminate in pockets 26, 28 in supporting bands 29, 30 which are respectively laced to the upper arm 31 and forearm 32 by means of laces 34, 35 on the support bands 29, 30. In Fig. 3 a similar joint assembly 11 is which are held together by means of a longitudinal link 50 and a transverse link 51.

In greater detail, as shown in Fig. 6, it will be seen that the lower brace bar 46 has an outwardly extending knuckle 52 at its end, the knuckle defining a recessed portion 54,

at its end of approximately the width of the upper brace bar 48. The lower brace bar contains a pin hole 55 near its end and the second pin hole 56 in the knuckle portion 52. The upper brace bar 48 also contains two pin holes 58, 59, the lower pin hole 59 being adjacent the end 60 of the upper brace bar 48.

Similarly it will be seen that the transverse link 51 contains pin holes 61, 62 adjacent its ends. The longitudinal link 50 also contains pin holes 64, 65 adjacent its ends.

The assembly of the joint is completed by riveting four pins in place in the appropriate pin holes, the longitudinal link pins 66, 68 being secured to the lower brace bar far pin hole 55 and the upper brace bar far pin hole 58. The pins are secured in place by mushrooming their ends or by any other suitable means after they are in I place for pivotal engagement through their respective pin holes. The transverse link pins 69, 70 pass through the transverse link pin holes 61, 62 and into the upper brace bar pin hole 59 and lower brace bar knuckle pin hole 56. The sequential operation of the joint is illustrated in Figs. 7 through 11. There it will be seen that in Fig. 7 where the joint is in its folded position with a lower brace bar 46 approximating a parallel relationship with the upper brace bar 48 there has been a physical separation of the two brace bars. The recess 54 of the lower brace bar 46 stands in spaced relation to the lower end 60 of the upper brace bar 48. The longitudinal link 50 and the transverse link 51 are in parallel relationship.

Then, as shown in Fig. 8, as the joint is moved toward the extended relationship, the transverse link 51 begins to rotate through its orbit at a faster rate than the longitudinal link 50. By the time the joint has arrived at the relationship shown in Fig. 9 where the lower brace bar 46 is in approximate perpendicular relation to the upper brace bar 48, the longitudinal link 50 and the transverse link 51 stand in approximately a perpendicular relationship. The recess 54 adjacent the knuckle portion 52 of 2,877,033. Patented y In Fig. 1 the knee brace v V I T gamma 3 the-lower bracebar 46 migrates into a closure spaced relationship with an upper brace bar end'60th'an was the case in the folded condition illustrated in Fig. 7. In Fig. 1.0 itwillbe seen that the.joint approximates the extended position. The recess.5"4loffthe. lower brace b'ar.46"is in. closed proximity to. theencl 60"ofthe upper brace b'ar 48,1the longitudinallink 50 still remains in approximate perpendicular relationship with the-transverse link 51;.

The extended position of the vjoint assemblyll'is shown in Fig. 11. There it will be seen that'the end eWof'thel upper brace bar 48 abuts the recess 54 of the knuckle 52jof'the lower brace bar 46.

Inreview, it is apparent that as the joint is. moved: fromithe extended position,asf-shown in Fig, 11,10 the folded position, as shown in Fig. 7, ,therelationship'of the brace barsis altered and. a lateral separation effected. At the same time, thetransverse link and longitudinal links 51; 50 alter their relationship from one of almost perpendicularaxes to a relationship of parallel axes. This action duplicates faithfully the action of the knee joint of It also follows closely the action of thehip; Were it not for" the use of. a joint providing this a human. joint. motion, the hip joint brace, such as shown in Fig; 3,

would bind when the patient was in'the seated position,

although it might serve satisfactorily for walking. Sim ilarly in the elbow and knee joints abinding effect isvexperienced at the supporting bands when the joints begin to approach the folded relationship.

Thejoint construction as shown may be combined'with a'unique lock assembly mechanism 75 as illustrated in 1 Figs. .12 and 13.. The lock assembly isiintendedfor'lock ing the joint. in extended positionas'shown'in'Fig. 11 of the. sequential movement of the joint; The lock'assembly itself contemplates a locking arm' 76 with an angled extension 78. The extension'78 is secured to the upper brace bar 48 by means of a screw79 threaded into the upper brace bar 48. A lockingpawl 80 extends'from the inner section ofthe locking handle'76-and extension 78 and presents a downwardly 'curvedengaging face "81; As shown'in Fig; 13, the joint is locked by depressing thelocking handle 76 until the face 81 on" the locking pawl BOengagesthe curved portion82 of the knuckle 52. The locking action thereby efiFected'is-in a sense self-enter gizing. as any effort to bend the joint merely forces the locking pawl 80 more firmly into a jammed relationship between the knuckleSZ and the upper brace bar '48 An additional reinforcing shoulder-85 maybeprovided to lock the end 60 of the upper brace bar 48 againstside' sway;

The construction-which has been shown contemplates the' conventional brace bars in prosthetic'devices known and widely used. One brace bar, however, has been modified to provide a'knuckle portion 52 and'adjacent recess portion 54. Onlytwo' connecting links, the longitudinal S and the transverselink 1, are required tocomplete the assembly; Because the longitudinal and transverse links 50, 51 are pivotally secured to opposite sides of the brace bars 46-, 48,- additional rigidity is impartedto the joint. As illustrated in Figs; 12and'l3, the joint isreadily adaptable for locking by a very simple but effective locking assembly' 75.

Because of the simplicity and rugged nature of the joint; it maybe inexpensively manufactured' on a mass production'b'asis. In addition, the joints motion renders it almost universal in adaptation as a knee, hip, and'el bow joint.

It-will be obvious from the-foregoing'thatvarious-- dimensions and proportionsmay; be'employed in the illustrative joint; In*practice;'however, it has been found that in a majorityof applications the efiective'length of the longitudinal link- 50' should'approximate or exceed twice the efiective length .of-the transverse link 51. By efiectivelength reference is madeto the .distance between.

thfecenters ofthe pivotpins 66,68, 69, ,7'0; Therecess: s htoftcourse, is governed- .principally by thewidth of the;

. 4: upper brace bar end 60. The knuckle 52 has an efiiective width approximating or exceeding that 'of're'cess 54, the effective width being the distance from the center of the knuckle pin 69 center to the rear edge of the upper brace bar 48.

Although a particular embodiment of the invention has been shown and described-r in full here, there is no intention to thereby limit the invention to the details of such embodiment on the contr-ary, the intention is to cover all modifications, alternative embodiments,.,usages and'equivalents of itheartificialljoint as fall within the spirit and scope of'the invention, specification and appendedflclaims;

I claim as my invention;

1. An artificiahjoint'comprising, in combination, an upper bar and a lower bar meeting at their ends, a knuckle extending from the lower bar end, a first link pivotally connected .to the .two bars across their joint,

a second link pivotally,v connected to the knuckle .andithe.

other bar end, and a lockingimechanism. comprisinga lever pivotally connectedto the upper bar end," the lever having a pawl whichengages the lower barknuckle thereby locking the joint;

2'. An artificial joint comprising,.in combination, anv

upper bar andfa lower'bar thelower extremity bar. being characterized by an upwardly and outwardly extending knuckle defining a recess whichreceives an endoff thev upper bar, a first link across thejunction-between the end of the upper barand lower bar recess, thefirst link beingpivotally connected at bothendsto the upper andlower bars, and a second linkpivotally connected at one end'to the upper bar end adjacent the joint with the lower bar recess and pivotally, connected at the other endto the lower bar knuckle, the orientation and proportion of the links and pivots being such that when the bars are folded their axes converge in the direction of the joint.

3; An artificialjoint comprising, in combination an upperb'a'r and a lower bar, the lower bar being characterized by an upwardly and' outwardly extending knuckle defininga recess'which receives an end of the upper bar, a first link across the junctionbetween the endof the .upper bar and lower bar recess, the first link. beingpivotally connected at both ends to the upper end and'lower bars, and'a second link pivotally connected atone end'to the upperbar end adjacent the joint with the lower barrecess and pivotally connected atthe other end to the lower extremity knuckle, the first link being at least twice the. lengthbetween pivots as the second link.

4. An artificial joint. comprising,,in combination; an upper bar. and a lower bar, the'lower bar being characterized by an upwardly and outwardly extending,

knuckle. defining a recess-which receives an end of'th'e upper bar, a" first link across the-junction between'the end ofthe upper bar and lower bar recess, the first link beingpivotally connected at both ends to the upper and lowerb'ars, asecond link pivotally connected at one end to"the.upp'er barvand adjacent the joint with the lowerbar recess and pivotally connectedat the other end-to the.lower bar knuckle, and alocking mechanism cornprisingja lever pivotally connected to the upper bar,'tlielever having apawl which engages the lower bar knuckle thereby locking the joint.

References Cited in the file of this patent UNITED STATES PATENTS f 

